Researchers of Bharathidasan University’s Department of Remote Sensing, the lead agency of a Department of Science and Technology-sponsored research study, on January 20 claimed to have found traces of an ancient port city buried undersea, at a depth of 50-100 metres, about 30-40 km off the coast of the present-day Poompuhar in Mayiladuthurai district.
The city, they said, was spread over about 250 sq. km, complete with a huge harbour, a lighthouse, ship and dockyards, and settlements.
The study covered the coastal area and about 1,000 square kilometres of the offshore area in the Bay of Bengal, and the findings were based on satellite, the General Bathymetry Chart of the Oceans (GEBCO) and multi-beam eco sounder (MBES) data. The MBES data were collected by the National Institute of Ocean Technology, Chennai.
“A major finding, based on a study of the past sea levels, is that Poompuhar is not just 2,500 years old as believed widely and might be more than 15,000 years old. It might be one of the oldest port cities in the world,” said SM. Ramasamy, Professor of Eminence and national coordinator, Project Poompuhar.
Poompuhar, also known Kaveripoompattinam, was submerged by the sea, and there are references to this in the Tamil epic Manimekalai. “The disappearance of the port city remained a mystery. We set out to digitally reconstruct the history of Poompuhar with the support of the Department of Science and Technology, with an initial funding of about ₹8.90 crore in 2019,” Professor Ramasamy said.
The studies carried out using GEBCO data showed a series of three deltas of the Cauvery, which run up to 40 km in the sea. The MBES data led to the discovery of a major coastal land system with sand banks, backwaters, beach ridges, rivers, estuaries and ancient shorelines. “We also inferred a scientifically designed harbour, about 11 km long and 2.5 km wide, running from north to south, with a number of canals meant for movement of big vessels and turning them. In between, there are broad plateaux which could have been used for loading, unloading and storing of merchandise.”
To the east of the harbour were 70-80 docks in north-south direction for a distance of 30 km for berthing ships. To the north were settlements with cluster of houses covering an area of about four square kilometres. Further up north were rowed settlements with compound walls. About 10 km away from the harbour on the north was a lighthouse, with a spiral staircase as evident from the pillar relics.
Several geological features such as deep river cut valleys of the Cauvery river system and submarine canyons were interpreted on the sea floor. They indicate that the Poompuhar region was prone to floods, tsunamis and accelerated impact of sea level rise and cyclone-induced surges. The port city had probably been relocated and rebuilt repeatedly owing to such natural occurrences. The seventh redevelopment was probably about 2,500 years ago and it might have submerged due to rise in sea level about 1,020 years ago.
Further studies, including underwater photography, are under way to corroborate the findings, and the project is expected to conclude in about a year, Professor Ramasamy said.
At a press conference to announce the findings, M. Selvam, Vice- Chancellor, Bharathidasan University, observed that the use of technology has helped learn more about the ancient port city of Tamil Nadu, going beyond its recorded history.
A dozen institutions, including Gandhigram Rural Institute, Tamil University, Annamalai University and Bharathiar University, besides a clutch of private institutions, are part of the inter-disciplinary and inter-institutional research project.